matplotlib-devel

Re: [matplotlib-devel] [Matplotlib-users] Double zooming with twinx

[Manuel M. <mm...@as...>]

Paul Smith wrote:
> I'm plotting two curves in one subplot with twinx to allow different y scales. 
> The script below is an example. 
> When zooming in using zoom-to-rect on Tk's navigation toolbar2 (TkAgg is my 
> backend) I think the x axis part of the zoom is happening twice. Rubberbanding 
> the example from x=20 to 80 results in a zoomed x range of about 32 to 68, 
> which is about what you'd expect for zooming with the same range twice. 
> 
> Is there a way of restricting this to only one zoom?
> 
> Paul
> ------------
> from pylab import *
> f=figure(1)
> ax1=f.add_subplot(111)
> ax1.plot(arange(100))
> ax2=twinx(ax1)
> ax2.plot(-arange(100),'g')
> draw()
> 

Hi,
there was the above mail on the users list.

The problem is that "release_zoom" in backend_bases.py is called twice 
in the above case if zoomed to a twinx'ed plot. One way to fix this 
behavior is to set a "twin" attribute to the axes instance. Attached is 
a patch against the 0.91 trunk.

John: is this okay or is there a better way to fix the problem?

Manuel

Re: [matplotlib-devel] [Matplotlib-users] Double zooming with twinx

[Manuel M. <mm...@as...>]

Manuel Metz wrote:
> Paul Smith wrote:
>> I'm plotting two curves in one subplot with twinx to allow different y 
>> scales. The script below is an example. When zooming in using 
>> zoom-to-rect on Tk's navigation toolbar2 (TkAgg is my backend) I think 
>> the x axis part of the zoom is happening twice. Rubberbanding the 
>> example from x=20 to 80 results in a zoomed x range of about 32 to 68, 
>> which is about what you'd expect for zooming with the same range twice.
>> Is there a way of restricting this to only one zoom?
>>
>> Paul
>> ------------
>> from pylab import *
>> f=figure(1)
>> ax1=f.add_subplot(111)
>> ax1.plot(arange(100))
>> ax2=twinx(ax1)
>> ax2.plot(-arange(100),'g')
>> draw()
>>
> 
> Hi,
> there was the above mail on the users list.
> 
> The problem is that "release_zoom" in backend_bases.py is called twice 
> in the above case if zoomed to a twinx'ed plot. One way to fix this 
> behavior is to set a "twin" attribute to the axes instance. Attached is 
> a patch against the 0.91 trunk.
> 
> John: is this okay or is there a better way to fix the problem?
> 
> Manuel
> 

Ups - the last patch didn't work correctly since the y-axis of the 
twin'ed plot wasn't scaled correctly. So I try it again ;-)

Manuel

Re: [matplotlib-devel] Double zooming with twinx

[Manuel M. <mm...@as...>]

Hi,

   I have fixed the double-zoom Bug in the trunk (revision 5053), but 
not in the 0_91maint branch. In 0.91 it's not so easy to find out 
whether an axes is shared with another (cbook:Group is nice ;-) ) For 
0.91: is it always guaranteed that the release_zoom event for the master 
is called before that of the shared axes ? (I don't think so.) Then it 
would be more easy to test for the shared axes ...
   So there is still the old solution (see previous post) to introduce 
an argument twinx,twiny #%$(/"/'+*#*# I don't like that.

Manuel

Re: [matplotlib-devel] [Matplotlib-users] Double zooming with twinx

[John H. <jd...@gm...>]

On Mon, Apr 7, 2008 at 8:38 AM, Manuel Metz <mm...@as...> wrote:

>  The problem is that "release_zoom" in backend_bases.py is called twice in
> the above case if zoomed to a twinx'ed plot. One way to fix this behavior is
> to set a "twin" attribute to the axes instance. Attached is a patch against
> the 0.91 trunk.
>
>  John: is this okay or is there a better way to fix the problem?


Hey Manuel,  thanks for fixng this.  I don't think it is critical that
this be fixed on the maintenance branch since it is a relatively small
bug (only applies in twinned axes) but I have a minor suggestion for
you in the fix for the trunk.  It is not a good idea for a class
outside the axes to access a "protected" "_twinx" attribute.  Probably
better is to either make the attribute public by naming it "istwinx"
or something like that, or make a method.

JDH